Generally, there have been attempts to perform a minimally invasive surgical (MIS) procedure. Such MIS techniques are aimed at reducing the amount of extraneous tissue that is damaged during diagnostic or surgical procedures, thereby reducing patient recovery time, discomfort, and deleterious side effects. The most common form of such procedures is laparoscopy, which is used for minimally invasive inspection and surgery inside the abdominal cavity. To perform such MIS procedures, a surgeon needs special instruments. The surgeon passes these instruments through a small incision of an abdominal wall to a surgical site and manipulates them from outside the abdominal wall by sliding them in and out through the abdominal wall, rotating and pivoting them against the abdominal wall. However, it has been found that a high level of dexterity is required to accurately control such instruments. And, the surgeon has no flexibility of tool replacement. Additionally, he or she experiences difficulty in approaching the surgical site through the incision. The length and construction of many instruments reduces the surgeon's ability to feel forces exerted by the surgical site on the instruments. Further, human hands typically have at least a minimal amount of tremor. The tremor further increases the difficulty of performing minimally invasive surgical procedures. So, only a relatively small number of surgeries have been performed due to limitations in required instruments, techniques and the surgical training.
Therefore, minimally invasive surgical robotic systems have been currently developed to increase a surgeon's dexterity when working within an internal surgical site as well as to allow a surgeon to operate on a patient from a remote location while monitoring a procedure by means of, e.g., a viewer which displays a three dimensional image of the surgical site via a camera. By means of the robotic systems, the surgeon can manipulate surgical instrument movements without directly holding and moving the instruments by hand. In such robotic systems, the surgical instruments can be precisely operated and be remotely controlled in a minimally invasive manner.
A robotic surgery is getting increasing attention with the wider application of the laparoscopic surgery. Actually, surgeons can do more efficient surgery with the enhanced dexterity and intelligent assistance provided by the robotic system.
Conventional robotic surgical systems are disclosed in e.g., U.S. Pat. No. 6,102,850 entitled “Medical Robotic System”, and U.S. Pat. No. 6,364,888 entitled “Alignment of Master and Slave in a Minimally Invasive Surgical Apparatus”. However, up to the present, the currently commercially available robotic surgical systems have drawbacks for abdominal surgery such as a huge system with bulky robotic arms, expensive cost, and so forth. Such a robotic system requires a large installation space and can not fully ensure an accurate surgical procedure.